[Techtoolslist] EPROM Programming Woes...

[Martin Olsson]

Jess!

The "tricks" I have is:

Make sure that the window of the EPROMs are thoroughly/perfectly cleaned so the UV light can penetrate properly.

Make sure the erasers UV light is good, if you have another UV eraser try that one as well and also set it for a longer time/period.

Make sure that you position the EPROMs properly inside the eraser.

Make sure that the set voltages are 100% correct for the specific EPROM you're programming and the programming speed and algorithm used as well. If you don't know 100% that you can trust the software of the EPROM burner then take a look at the datasheet for the specific EPROM you're programming.

Also, take another EPROM that you have (known good) and just test/isolate with that (if you only have one eraser it's essential that the light is doing the job properly (I know that some EPROMs erase very easily/quickly but the ones you're trying now may be more difficult to erase perhaps?)).

I also own a 29B but I don't have much experience working with it. The programmer I use and have used for like 25 years is the All-07 (Hi-Lo Systems), in short, it's very good and reliable but was extremely expensive back in the day. The All-07 is DOS based but the software for it is good and professional and I've yet to come across wrong values of voltages etc. Apart from that I also have a TL-866A (cheap USB programmer) but that is not as reliable and trustworthy as the good old All-07.

Regarding the fault you're getting (that it stops immediately when you start the programming) I would say that from my experience that would indicate that the EPROM is not properly erased. Since you have so many EPROMs it's unlikely that they are all defective.

Good luck!


/Martin!

-----Original Message-----
From: Techtoolslist [mailto:techtoolslist-bounces at flippers.com] On Behalf Of Jess Askey
Sent: den 28 mars 2018 07:01
To: Technical Tools Mail List <techtoolslist at flippers.com>
Subject: [Techtoolslist] EPROM Programming Woes...

Heya Folks...

I have had a need to program a bunch of EPROMs lately (27128 varieties) and Im not sure if there are sunspots or something, but I can't seem to program anything on either my 29B OR my Intronics USB Programmer... I have successfully programmed like 4 EPROMs out of like 40 attempts. My EPROM's are old pulls from either Atari boards or other used ones I have acquired over the years in storage sticks.

They are either

ST 27128A
Fujitsu 27128
SEEQ 27128
TI TMS27C128

Im being fairly careful about the programming voltages and the 29B identifies the IC before programming it.

On the 29B I just get an Error #22 Programming Error right away.

Sorta the same thing on my Intronics.... Set it up, verify blank, program, error right away.

Are these just too old? Anyone have any good tricks?  The strange part is that I was having this exact same issue last night, then all of a sudden my 29B programmed 3 in a row just fine... today, nothing.

Thanks
Jess

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